The really scary sideof Alice

Alice Cooper is living the rock'n'roll dream. He's perched on the sofa of a luxury hotel suite, shortly after the sun has risen over the nearby Hollywood Hills, with a half-empty bottl e in his hand, and an enormous flat-screen TV blaring. Could the mise-en-scène be more perfect? Not unless he was to leap up, wrench the telly from its wall socket, and toss it off the balcony ... where tradition dictates that it would land with an almighty splosh in the swimming pool.

That will not be happening today, however. It is 9am. His half-empty bottle contains nothing more potent than vitamin water. "The Coop", as his PA calls him, has risen early, showered, and is now eating a wholesome breakfast of sunflower seeds and miniature chocolates. There are dark smudges around his eyes, but hard living, and outrageous self-abuse are not to blame. They come from a fresh dusting of mascara.

So, here's the thing about Alice Cooper: onstage, he's now been at the cutting-edge of shock-rock for an incredible 40 years. Chickens have died at his stage shows. Nooses have been hung round effigies. Fake blood has been sprayed like ketchup, and outraged politicians have called for his music to be banned. He's been there, done that, sold the black T-shirts. But offstage? Things couldn't be more different.

The Coop, whose real name is Vincent Damon Furnier, turns out to be a man of two parts. To the public, he is famous for wearing leather and singing tracks with such terrifying titles as "I'll Bite Your Face Off". His gigs are noteworthy for gory pieces of performance art, in which he pretends to stab women, or decapitate babies, or canoodle with live pythons. In private, however, he's a pillar of respectability: married for 36 years, teetotal for almost as long, with two grown-up children. At home, in suburban Arizona, he's big in the local church, and addicted to the bourgeois pursuit of golf, which he plays every day.

In person, Cooper also turns out to be charming and extremely well-spoken. And this disconnect, between his private and public persona, is probably at the heart of his appeal. To see Alice perform, wreaking havoc in leather, studs and back-combed hair, is to experience a glorious piece of artifice which will never grow old. The fact that we know it's all an act makes him a sort of a national treasure. A genuine legend, whose vaudeville falls on just the right side of self-parody.

We meet on the morning of the launch of Cooper's 25th studio album. The new record's called Welcome 2 My Nightmare, a sequel to his Seventies classic, Welcome to My Nightmare. Later that day, he's due to play Whisky a Go-Go, a Hollywood nightclub which became legendary in the 1960s. "The last time I played there was about 40 years ago," he says. "Back then, we were supporting a little-known band called Led Zeppelin."

After that, Cooper and his band are due to continue a tour that consumes roughly six months of their annual calendar. This month, they're swinging through half a dozen UK venues, including Alexandra Palace tonight, where he'll stage a special "spooky" show. "I'm trying to bring the idea of Hallowe'en to London," is how he explains the project.

Behind the blood, gore and arachnids, Cooper can turn out top-quality rock'n'roll. His most famous hits, such as "Welcome to My Nightmare" or "Poison" or "No More Mr Nice Guy" are insanely competent pieces of music: catchy, exhilarating, and multi-layered; in fact, Bob Dylan once declared Cooper to be the most underrated lyricist of his generation.

Cooper's newer stuff keeps him relevant, too. Welcome 2 My Nightmare has a cameo from Ke$ha, and one of its videos features Johnny Depp performing with "Coop" at London's 100 Club. In the US, the record debuted this month at 22 on the Billboard charts, making it his best release since 1989's platinum selling Trash. Like many old-stagers, he credits at least some of that success to a woeful lack of competition.

"Rock'n'roll has to be upsetting. It has to piss someone off a little bit," he says. "But these songs young bands are putting out today, well, Ozzy, me, Deep Purple, any of the bands from our era, we'd have thrown them away. Today's lot just want to fit in. Where I come from, the idea of rock is not to fit in."

For all his devotion to pissing people off, Cooper can also sometimes be disarmingly conservative, particularly when he strays off the topic of heavy-metal music. When we start discussing his life in Arizona, for example, he reveals he's friendly with local Senator John McCain, the elderly former Republican presidential candidate.

It turns out that The Coop is in many ways a right-leaning tea-partier. He energetically advocates a flat income tax (15 per cent would be fair, he says) and bold moves to rein in America's national debt. On social issues, he has much in common with the evangelical Texas Governor and current Republican presidential front-runner Rick Perry.

Discussing life's big questions with a man who sometimes wears a cape in public feels a touch surreal. But Cooper is on a roll. It turns out he also thinks George Bush gets an unfair shake from the media. "When people say, 'Bush went to war', I say, 'Wait a minute!'. He's got to go through 150 people to do that, and they all agreed to go to war. So why does he get all the blame?"

Fox News politics aside, Alice Cooper hasn't always been such a darling of the Right. Born in 1948 and raised in a Phoenix trailer park, he began performing at high school in a band called first the Earwigs and then the Spiders. In 1968, the band was signed by Frank Zappa, who encouraged them to start making headlines.

The first step was to adopt a more memorable stage name. "I created Alice then, out of necessity," is how Cooper recalls it. "I looked around at rock'n'roll, in the late Sixties, I felt that it didn't have a villain. It did not have the personification of evil. It had Jim Morrison, but he was more of a victim. And I wondered: 'Where is this character who walks on stage and makes everyone take a step backwards?' That's what Alice became."

After that, the group merely needed to seal their reputation for outrageous behaviour. That was achieved at a gig in Toronto in 1969, when a live chicken was thrown on to the stage. Thinking it would fly away, Cooper threw the creature back into the crowd. It was torn to pieces.

A year later came his first really successful album, Love it to Death. In 1972, he hit the big-time with the number one single "School's Out". By 1973, Labour MP Leo Abse attempted to have his UK tour banned, on the grounds that his track "Cold Ethyl" was an "anthem of necrophilia".

There were moments, mostly during the 1970s, when being the bad-boy of popular music started to exact a toll on Cooper. "When I came to LA, the first people I met were the Doors and the Mothers of Invention. So I'm trying to keep up with Jim Morrison drink for drink," he recalls. "I'm trying to keep up with Janis Joplin and Keith Moon, drink for drink ... These guys went on, and on, and then one day, they died."

By the time he'd reached his thirties, Cooper was drinking a bottle of whisky a day. But the party ended in 1981, when his wife, Sheryl, dragged him off to rehab. "I was 33. I'd had a great run, and didn't die. Close. Very close. I was getting up in the morning and throwing up blood."

In rehab, Cooper realised that he needed to put clear blue water between his private personality and his stage persona. He achieved that by stumbling on a new addiction: golf. For the past 30 years, he's played relentlessly and obsessively. At first, he had to keep it secret from fans ("Golf is what their Dad plays") but in recent years, he's decided to embrace the sport, regardless of its image.

"I'm now invited to all the best clubs, because I'm a two handicap. Here's the deal, though: every heavy-metal band I know now plays golf. Pantera play. In Metallica, two of the guys play. Almost every band I know does. Because when you're on the road, in some town like Wichita, what else is there to do? There's something really satisfying about it. Almost like a drug. If you make a great shot, it feels like taking a great hit."